Process for producing olefins

Abstract

This method for producing an olefin is characterized in that contact of a C5 saturated hydrocarbon and a dehydrogenation catalyst containing at least one metal selected from among transition metals is performed in the presence of hydrogen sulfide to perform a dehydrogenation reaction of the C5 saturated hydrocarbon. According to the present invention, it is possible to provide a method which is for producing an olefin through dehydrogenation of a C5 saturated hydrocarbon and by which the selectivity of diolefins in a product is high.

Description

Technical Field

[0001] The present invention relates to a method for producing olefins by dehydrogenating a saturated hydrocarbon having 5 carbon atoms to produce olefins.

Background Art

[0002] In the petroleum refining process, saturated hydrocarbons having 5 carbon atoms are components contained in fuel oil, and as long as a certain amount of demand for fuel oil can be expected, there will be no problem of surplus of saturated hydrocarbons having 5 carbon atoms.

[0003] However, in the future, since a decrease in the demand for fuel oil is expected, it is presumed that saturated hydrocarbons having 5 carbon atoms will become surplus substances in the future. Therefore, it becomes necessary to shift saturated hydrocarbons having 5 carbon atoms from fuel oil raw materials to other raw materials.

[0004] One of the countermeasures is to dehydrogenate saturated hydrocarbons having 5 carbon atoms to convert them into olefins having 5 carbon atoms and use them as petrochemical raw materials.

[0005] Here, conventionally, as a method for dehydrogenating a saturated hydrocarbon having 3 or 4 carbon atoms to produce an olefin having 3 or 4 carbon atoms, for example, a method of directly dehydrogenating propane using an alloy catalyst composed of alumina-zinc oxide, or a method of directly dehydrogenating n-butane using a heterogeneous dehydrogenation catalyst such as a platinum-tin-alumina catalyst has been disclosed (Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Disclosure of the Invention

Problems to be Solved by the Invention

[0007] However, Patent Documents 1 and 2 do not disclose a method for producing an olefin having 5 carbon atoms by dehydrogenating a saturated hydrocarbon having 5 carbon atoms.

[0008] When a saturated hydrocarbon having 5 carbon atoms is used as a raw material and dehydrogenated, the resulting olefins include monoolefins and diolefins. Diolefins are highly useful in that they are used in synthetic rubbers, fine chemicals, resins, and the like. Therefore, there is a demand for the development of a method for producing an olefin with a high selectivity for diolefins in the dehydrogenation of a saturated hydrocarbon having 5 carbon atoms.

[0009] Accordingly, an object of the present invention is to provide a method for producing an olefin by dehydrogenating a saturated hydrocarbon having 5 carbon atoms, the method being capable of achieving a high selectivity for diolefins in the product. Means for Solving the Problems

[0010] The above problems are solved by the following present invention. That is, the present invention (1) While supplying hydrogen sulfide, comprises contacting a saturated hydrocarbon having 5 carbon atoms with a dehydrogenation catalyst containing at least one metal selected from Fe, Co, Ni, Mn, Cu, Mo, Cr, V, Ti, Ru, and Pd in the presence of hydrogen sulfide to carry out a dehydrogenation reaction of the saturated hydrocarbon having 5 carbon atoms. 、 the volume ratio of the hydrogen sulfide to the saturated hydrocarbon having 5 carbon atoms (hydrogen sulfide / saturated hydrocarbon having 5 carbon atoms) is 0.2 to 3.0, The present invention provides a method for producing an olefin, which is characterized by the above.

[0012] Further, in the present invention ( 2 ), the volume ratio of hydrogen sulfide to the saturated hydrocarbon having 5 carbon atoms (hydrogen sulfide / saturated hydrocarbon having 5 carbon atoms) is 1.0 to 3.0. The present invention provides a method for producing an olefin as described in ( 1 ).

[0013] Further, in the present invention ( 3) is characterized in that the reaction temperature of the dehydrogenation reaction is 500 to 700 °C (1) or (2) It provides the method for producing an olefin described above.

[0014] Also, the present invention ( 4 ) is characterized in that the reaction temperature of the dehydrogenation reaction is 500 to 650 °C (3) and provides a method for producing an olefin.

[0015] Also, the present invention ( 5 ) is characterized in that the reaction temperature of the dehydrogenation reaction is 500 to 550 °C ( 3 ) and provides a method for producing an olefin.

[0016] Also, the present invention ( 6 ) is characterized in that the reaction temperature of the dehydrogenation reaction is 550 to 650 °C ( 3 ) and provides a method for producing an olefin.

Advantages of the Invention

[0017] According to the present invention, there is provided a method for producing an olefin by dehydrogenating a saturated hydrocarbon having 5 carbon atoms, which can provide a method for producing an olefin with a high selectivity of diolefin in the product.

Embodiments for Carrying Out the Invention

[0018] The method for producing an olefin of the present invention is characterized in that the contact of a saturated hydrocarbon having 5 carbon atoms with a dehydrogenation catalyst containing at least one metal selected from transition metals is carried out in the presence of hydrogen sulfide to carry out the dehydrogenation reaction of the saturated hydrocarbon having 5 carbon atoms, which is a method for producing an olefin.

[0019] The saturated hydrocarbon having 5 carbon atoms according to the method for producing an olefin of the present invention is a raw material to be contacted with the dehydrogenation catalyst and is a target to be dehydrogenated by the dehydrogenation reaction.

[0020] Saturated hydrocarbons with 5 carbon atoms are hydrocarbons represented by C5H 12 and are hydrocarbons represented by 12 , and are n-pentane and 2-methylbutane. The saturated hydrocarbon with 5 carbon atoms may be any one of n-pentane and 2-methylbutane, or may be a mixture of two or more. As the saturated hydrocarbon with 5 carbon atoms, since the radical cation is more stable in the tertiary carbon than in the secondary carbon, 2-methylbutane is preferable in terms of improving the yield of olefin.

[0021] In addition, the saturated hydrocarbon with 5 carbon atoms may contain hydrocarbons other than the saturated hydrocarbon with 5 carbon atoms, for example, saturated or unsaturated hydrocarbons with 3 carbon atoms, saturated or unsaturated hydrocarbons with 4 carbon atoms, and unsaturated hydrocarbons with 5 carbon atoms.

[0022] The purity of the saturated hydrocarbon with 5 carbon atoms is not particularly limited, but is preferably 80% by mass or more, more preferably 85% by mass or more, and particularly preferably 90% by mass or more.

[0023] The dehydrogenation catalyst according to the method for producing an olefin of the present invention is a dehydrogenation catalyst containing at least one metal selected from transition metals. Examples of the transition metal contained in the dehydrogenation catalyst include Fe, Co, Ni, Mn, Cu, Mo, Cr, V, Ti, Ru, Pd, etc. Among these, Fe, Ni, and Co are preferable in terms of increasing the catalyst life, and Fe is particularly preferable.

[0024] The transition metal contained in the dehydrogenation catalyst is usually supported on a carrier. Examples of such a carrier for the transition metal include silica (SiO2), alumina (Al2O3), zirconia (ZrO2), ceria (CeO2), magnesia (MgO), titania (TiO2), and composite sulfides of these oxides and hydrogen sulfide. Among these, silica and alumina are preferable in terms of high stability and high selectivity of the product.

[0025] The supported amount of the transition metal in the dehydrogenation catalyst is preferably 0.5 to 70% by mass, particularly preferably 3 to 20% by mass in terms of atoms based on the total mass of the dehydrogenation catalyst. When the supported amount of the transition metal in the dehydrogenation catalyst is within the above range, active species of the transition metal are likely to be formed. The supported amount (%) in terms of the oxide of the transition metal in the dehydrogenation catalyst based on the total mass of the dehydrogenation catalyst is a value calculated by the formula "(mass of the transition metal present in the dehydrogenation catalyst converted to oxide / total mass of the dehydrogenation catalyst) × 100".

[0026] In the method for producing an olefin of the present invention, the dehydrogenation reaction of the saturated hydrocarbon having 5 carbon atoms in the hydrocarbon raw material is carried out by bringing the saturated hydrocarbon having 5 carbon atoms into contact with the dehydrogenation catalyst in the presence of hydrogen sulfide to obtain an olefin having 5 carbon atoms. In the method for producing an olefin of the present invention, the life of the catalyst can be extended by carrying out the contact between the saturated hydrocarbon having 5 carbon atoms and the dehydrogenation catalyst in the presence of hydrogen sulfide. On the other hand, in the method for producing an olefin, if hydrogen sulfide is not present during the contact between the saturated hydrocarbon having 5 carbon atoms and the dehydrogenation catalyst, the life of the catalyst will be shortened. In the method for producing an olefin of the present invention, the contact between the saturated hydrocarbon having 5 carbon atoms and the dehydrogenation catalyst may be carried out in the presence of hydrogen sulfide after pre-sulfiding the dehydrogenation catalyst by bringing hydrogen sulfide into contact with the dehydrogenation catalyst in advance, or alternatively, the contact between the saturated hydrocarbon having 5 carbon atoms and the dehydrogenation catalyst may be carried out in the presence of hydrogen sulfide without pre-sulfiding the dehydrogenation catalyst.

[0027] In the method for producing an olefin of the present invention, the method of contacting a saturated hydrocarbon having 5 carbon atoms with a dehydrogenation catalyst in the presence of hydrogen sulfide is not particularly limited. For example, (i) a continuous flow type reaction tower is filled with a dehydrogenation catalyst, and at one end side of the reaction tower, a saturated hydrocarbon having 5 carbon atoms is supplied together with a carrier while simultaneously supplying hydrogen sulfide, and at one end side in the reaction tower, the saturated hydrocarbon having 5 carbon atoms and hydrogen sulfide are mixed, and the mixture is brought into contact with the dehydrogenation catalyst, and the reaction product is discharged from the other end side of the reaction tower; (ii) a continuous flow type reaction tower is filled with a dehydrogenation catalyst, and a supply line of a saturated hydrocarbon having 5 carbon atoms is connected to one end side of the reaction tower. Through the supply line of the saturated hydrocarbon having 5 carbon atoms, a saturated hydrocarbon having 5 carbon atoms is supplied together with a carrier while hydrogen sulfide is supplied in the middle of the supply line of the saturated hydrocarbon having 5 carbon atoms, and the saturated hydrocarbon having 5 carbon atoms and hydrogen sulfide are mixed in the supply line of the saturated hydrocarbon having 5 carbon atoms, and the mixture is supplied to one end side of the reaction tower, and the mixture is brought into contact with the dehydrogenation catalyst, and the reaction product is discharged from the other end side of the reaction tower.

[0028] In the method for producing an olefin of the present invention, the volume ratio of hydrogen sulfide to the saturated hydrocarbon having 5 carbon atoms (hydrogen sulfide / saturated hydrocarbon having 5 carbon atoms) is preferably 0.2 to 3.0. When the volume ratio of hydrogen sulfide to the saturated hydrocarbon having 5 carbon atoms is within the above range, the selectivity of diolefin in the product increases.

[0029] In the method for producing an olefin of the present invention, the volume ratio of hydrogen sulfide to the saturated hydrocarbon having 5 carbon atoms (hydrogen sulfide / saturated hydrocarbon having 5 carbon atoms) is more preferably 1.0 to 3.0. When the volume ratio of hydrogen sulfide to the saturated hydrocarbon having 5 carbon atoms is within the above range, in addition to the increase in the selectivity of diolefin in the product, the selectivity of dehydrogenated products in the product (the total selectivity of monoolefin and diolefin) increases. Since monoolefin also has value as a petrochemical raw material, it is more preferable that the dehydrogenation rate is high.

[0030] In the method for producing an olefin of the present invention, the supply rate of the saturated hydrocarbon having 5 carbon atoms is preferably 0.1 to 50 mL / min, particularly preferably 1 to 10 mL / min.

[0031] In the method for producing an olefin of the present invention, the reaction temperature of the dehydrogenation reaction is preferably 500 to 700 °C, particularly preferably 500 to 650 °C, in terms of increasing the selectivity of diolefin in the product.

[0032] In the method for producing an olefin of the present invention, when increasing the selectivity of monoolefin in the dehydrogenated product, the reaction temperature of the dehydrogenation reaction is preferably 500 to 550 °C. Further, in the method for producing an olefin of the present invention, when increasing the selectivity of diolefin in the dehydrogenated product, the reaction temperature of the dehydrogenation reaction is preferably 550 to 650 °C.

[0033] In the method for producing an olefin of the present invention, monoolefin and diolefin are produced by the dehydrogenation reaction of the saturated hydrocarbon having 5 carbon atoms. Further, in the method for producing an olefin of the present invention, hydrocarbons having 1 to 4 carbon atoms as decomposition products and isomerized saturated hydrocarbons of the saturated hydrocarbon having 5 carbon atoms are by-produced. For example, when 2-methylbutane is used as the saturated hydrocarbon having 5 carbon atoms, 2-methyl-1-butene and 2-methyl-2-butene are produced as monoolefins, 2-methyl-1,3-butadiene is produced as a diolefin, and hydrocarbons having 1 to 4 carbon atoms and n-pentane are by-produced. Further, for example, when n-pentane is used as the saturated hydrocarbon having 5 carbon atoms, 1-pentene and 2-pentene are produced as monoolefins, 1,3-pentadiene, 1,4-pentadiene, and 2,3-pentadiene are produced as diolefins, and hydrocarbons having 1 to 4 carbon atoms and 2-methylbutane are by-produced.

[0034] Examples are shown below to more specifically explain the present invention, but the present invention is not limited thereto.

Examples

[0035] <Preparation of dehydrogenation catalyst> 2.0 g of silica, which is a catalyst support, was immersed in 30.0 mL of distilled water and degassed under vacuum at room temperature for 12 hours. Then, an aqueous iron(III) nitrate solution (an aqueous solution prepared by dissolving 1.6236 g of iron(III) nitrate in 10.0 mL of distilled water), corresponding to 10% by mass based on the total weight of the dehydrogenation catalyst, was added, and the mixture was further stirred for 2 hours. The resulting suspension was evaporated to remove water at 80 °C with stirring, and then calcined at 500 °C for 1 hour in a flow-through calcination furnace. The obtained catalyst was processed into pellets using a compression molding machine and then pulverized, and sized so that the particle size was 250 - 500 μm to obtain Catalyst A.

[0036] (Example 1) An inner diameter 8 mm × length 300 mm reactor was filled with the dehydrogenation catalyst obtained above (catalyst amount: 500 mg). Next, 2-methylbutane, hydrogen sulfide, and a carrier gas (helium gas) were supplied to the reactor at a supply rate of 50 mL / min at a ratio such that the volume ratio of hydrogen sulfide / 2-methylbutane was 0.2 and the volume ratio of 2-methylbutane / carrier gas was 0.1, while discharging the reaction solution from the reactor, and a dehydrogenation reaction was carried out at a reaction temperature of 550 °C. Next, the obtained reaction solution was analyzed using a gas chromatograph (column: VZ-7 (GL Sciences), analysis conditions: GC-FID, INJ 35 °C, COL 35 °C, DET 50 °C, flow rate 25 mL / min), and the yields and selectivities of the products are shown in Table 1.

[0037] (Examples 2 - 17, Comparative Example 1) The reaction was carried out in the same manner as in Example 1, except that the volume ratio of hydrogen sulfide / 2-methylbutane and the reaction temperature were as shown in Tables 1 - 4. The results are shown in Tables 1 - 4.

[0038] (Comparative Examples 2 - 5) A catalyst was prepared in the same manner as in Example 1, except that the metal amount of the catalyst was 20% by mass based on the total weight of the dehydrogenation catalyst and the calcination temperature was 700 °C. Using n-butane instead of 2-methylbutane, the reaction was carried out in the same manner as in Example 1, except that the volume ratio of hydrogen sulfide / n-butane and the reaction temperature were as shown in Table 5 and the supply rate was 25 mL / min. The results are shown in Table 5.

[0039]

Table 1

[0040]

Table 2

[0041]

Table 3

[0042]

Table 4

[0043]

Table 5

Claims

Claim 1: By performing the contact of a saturated hydrocarbon having 5 carbon atoms with a dehydrogenation catalyst containing at least one metal selected from Fe, Co, Ni, Mn, Cu, Mo, Cr, V, Ti, Ru, and Pd while supplying hydrogen sulfide in the presence of hydrogen sulfide, a dehydrogenation reaction of the saturated hydrocarbon having 5 carbon atoms is carried out. The volume ratio of hydrogen sulfide to the saturated hydrocarbon having 5 carbon atoms (hydrogen sulfide / saturated hydrocarbon having 5 carbon atoms) is 0.2 to 3.

0. A method for producing an olefin, characterized by the above.

2. The method for producing an olefin according to Claim 1, wherein the volume ratio of hydrogen sulfide to the saturated hydrocarbon having 5 carbon atoms (hydrogen sulfide / saturated hydrocarbon having 5 carbon atoms) is 1.0 to 3.

0.

3. The method for producing an olefin according to Claim 1 or 2, wherein the reaction temperature of the dehydrogenation reaction is 500 to 700 °C.

4. The method for producing an olefin according to Claim 3, wherein the reaction temperature of the dehydrogenation reaction is 500 to 650 °C.

5. The method for producing an olefin according to Claim 3, wherein the reaction temperature of the dehydrogenation reaction is 500 to 550 °C.

6. The method for producing an olefin according to Claim 3, wherein the reaction temperature of the dehydrogenation reaction is 550 to 650 °C.

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